This invention relates to billing information in an internet protocol multimedia subsystem (IMS) system and more specifically relates to charging data records (CDR) in an IMS system, information contained in these records, and the routing of the records.
Telephony systems have generated billing records related to each subscriber's account using CDRs. This has carried forward and is still used in newer systems, e.g. 3GPP and 3GPP2. For example in a 3GPP IMS system, network elements transmit session and event charging account request messages (ACR) to a charging data function (CDF) which in turn transmits this information to a billing system by way of a charging gateway function (CGF). However, the ACRs contain only limited subscriber data. Thus, service providers are required to process the CDR and rate the associated call based on the limited subscriber data contained in the ACRs. Service providers have a need for access to more complete subscriber data information while processing a CDR in order for the associated call to be rated/billed more precisely and for increased flexibility in billing.